Amp/Speaker/Ohm Question

stix_clgi · #1 10-12-2011, 08:46 PM

What's up TB! Quick question, I recently bought a used Ampeg B5r and was wondering what would happen if I connected three 8ohm cabs to it? It's rated at 500w @ 2 ohms, I figured three cabs takes it to like 3 ohms right? Or is this a recipe for blown amp delight?

brendanbassist · #2 10-12-2011, 08:49 PM

3x 8 ohm cabs would be 2.666 ohms. If the head is rated down to 2 ohms it should be fine.

JTE · #3 10-13-2011, 07:51 AM

3 ohms?!??! Where'd you get that? Parallel impedance (assuming all three loads are the same) is the individual impedance divided by the number of equal loads. So three 8Ω loads is 8/3 = 2.66 as brendanbassist says.

John

Oobly · #4 10-13-2011, 08:53 AM

Yup, 3 cabs = 2.66 ohms. Don't see any reason you shouldn't do it.

tgriley62 · #5 10-13-2011, 09:45 AM

I have also wanted to know how you hook up 3 cabs when your head only has 2 output jacks. Do you use some type of "Y" splitter to hook up 2 of the cabs & if this is the case wont the one cab be getting more power than the 2 that are sharing the other output jack?

Bass_Pounder · #6 10-13-2011, 09:50 AM

Quote:

Originally Posted by tgriley62

I have also wanted to know how you hook up 3 cabs when your head only has 2 output jacks. Do you use some type of "Y" splitter to hook up 2 of the cabs & if this is the case wont the one cab be getting more power than the 2 that are sharing the other output jack?

Most cabs have two inputs on them which are already wired in parallel.

You run a cable from the head to the 1st cab, then "daisy chain" the 2nd cab from the other connection on the back of the 1st cab.

Cab #3 can be run off of cab #2, or from another output from the head.

All cabs will recieve the same power as long as they are matching in ohm load.